When using "i think'' and ''i guess''? Hello everyone! I see the use of ''i think'' or ''i guess'' to express the same idea, but i don't know when to use each. Please, can you help me?

Can you help me?

Hello, everyone!

I am learning English, but my level is still not advanced. I would like to practice with someone who already knows a little Portuguese to facilitate conversation, can you help me? 

this text is correct? The population viability analysis is a relatively new tool that uses the concept of minimum viable population to predict the population dynamics of a species. In the order of the Chiroptera there is still a deficit of research with PVA, which demonstrates the need for more research in this area. The PVA is considered one of the most important strategies in conservation biology, being a preventive and corrective analysis, which can help prevent the decline and extinction of a population, besides assist in choice of adequate management for populations that are already vulnerable. The population viability analysis (PVA) was utilized to model the interaction between four colonies of Phyllostomus hastatus that comprise one population in Marambaia Island, municipality of Mangaratiba, in the state of Rio de Janeiro. The software used for this analysis was the VORTEX 9.99 and the results showed that this population is not be at risk of extinction or decline within a hundred years.

YOU CAN TO CORRECT THIS TEXT?

The population viability analysis is a relatively new tool that uses the concept of minimum viable population to predict the population dynamics of a group or species. In order of Chiropteras there is still a deficit of jobs with PVA, which demonstrates the need for more research in this area. The PVA is considered one of the most important strategies in conservation biology, with a preventive and corrective analysis, which can help prevent the decline or extinction of a population and help choosing adequate management practices for populations that are already vulnerable.
The population viability analysis (PVA) was used to model a population of Phyllostomus Hastatus in Marambaia Island, municipality of Mangalore in the state of Rio de Janeiro. The software used for this analysis was the VORTEX 9.99 and the results showed that this population is not at risk of extinction or decline within a hundred years.


ORIGINAL TEXT

 

 

A análise de viabilidade populacional é uma ferramenta relativamente recente que usa o conceito de população mínima viável para prever a dinâmica populacional de um grupo ou espécie. Na ordem dos Chiropteras ainda existe um déficit de trabalhos com PVA, o que demonstra a necessidade de mais pesquisas nessa área. A PVA é considerada uma das estratégias mais importantes na biologia da conservação, sendo uma análise preventiva e corretiva, na qual pode ajudar a evitar o declínio ou extinção de uma população e auxiliar na escolha de manejos adequados para populações que já estão vulneráveis.
A análise de viabilidade populacional (PVA) foi utilizada para modelar uma população de Phyllostomus hastatus na Ilha da Marambaia, munícipio de Mangaratiba, no estado do Rio de Janeiro. O software utilizado para essa análise foi o VORTEX 9.99 e os resultados demonstraram que essa população não corre risco de extinção ou declínio dentro de cem anos.  

How do you say Hello, guys! How do you say "pijama (portuguese)" in English, please?

Doubt Hello everyone! I would like to know when i using "work" or "job", there is a rule for this? Thanks! :)